Black zone

[Talisman1]

When I scroll down or up to see the list of my apps, in the right bottom corner the black zone in the shape of triangle is generated. It only happens in the list of apps, not in other places. Can you help me on this issue? S9

[johnogz]

aren't you referring to the triangular shape due to your wallpaper?

[Talisman1]

I think it is not due to the wallpaper. Because I changed the wallpaper several times but the result is the same.